Set-up for manufacturing spray-dried powders

ABSTRACT

The present invention relates to a method of manufacturing spray-dried powders. During the process, a solvent is used. The process is done in multiple steps such that the emulsification mass ratio is low when removal of the solvent is started. Preferred solvents are isopropyl acetate and ethyl acetate. The invention also relates to a set-up to run the inventive process at industrial scale.

TECHNICAL FIELD

The present invention relates to the manufacturing of spray-driedpowders which are water-dispersible despite of comprising a fat-solublecompound. A typical fat-soluble compound is beta-carotene. Such powdersmay be used for the coloration of food and beverages.

BACKGROUND OF THE INVENTION

To color food and beverages, edible colorants are needed. Many ediblecolorants are fat-soluble. To make fat-soluble colorantswater-dispersible, they need to be encapsulated by an edible emulsifier.Well-known edible emulsifiers are gelatin and modified starch.

Water-dispersible powders comprising a fat-soluble compound may bemanufactured by spray-drying. To do so, a dispersion which comprises (i)water and (ii) particles is spray-dried. The dispersion's particles havea fat-soluble compound in the core which is surrounded by an edibleemulsifier. To be useful in the coloration of food and beverages, theparticles must be very small. Typically, the particles have a particlesize of less than 1 μm.

Dispersions which are suitable for spray-drying can be manufactured indifferent manners.

EP 0 937 412 B1 discloses a process for the preparation of a pulverouscarotenoid, retinoid or natural colorant preparation, wherein the activeingredient is finely divided, which process comprises the steps of

a) forming a suspension of the active ingredient in a water-immiscibleorganic solvent, being dimethyl carbonate, ethyl formate, ethyl orisopropyl acetate, methyl tert. butyl ether or methylene chloride,optionally containing an antioxidant and/or an oil,

b) feeding the suspension of step a) to a heat exchanger and heatingsaid suspension to 100-180° C., whereby the residence time in the heatexchanger is less than 5 seconds,

c) rapidly mixing the solution of step b) at a temperature in the rangeof 20-100° C. with an aqueous solution of a swellable colloid optionallycontaining a stabilizer,

d) removing the organic solvent and

e) converting the dispersion of step d) into a pulverous preparation.

In example 1 of EP 0 937 412 B1, a powder comprising gelatin and havinga carotene content of 11.6% was obtained. Whereas such a powder isuseful, there is a need for powders on gelatin basis which have a highercarotene content. To get a higher carotene content in the powder, thedispersion which is spray-dried must have a higher carotene content,too.

The problem to be solved by the present invention is the provision of anaqueous dispersion which can be converted into a water-dispersiblepowder (e.g. by spray-drying) and/or which has a high content of atleast one fat-soluble compound such as a fat-soluble colorant.

The manufacturing of such dispersions is a technical challenge. Ideally,the quality of the dispersion is very good such that there is hardly anyfilter residue when filtering the dispersion over 2 g Hyflo Super Cel®on a filter paper (Whatman 1001-070, Grade 1, median pore size of 7.0μm).

Thus, a more specific problem to be solved by the present invention isthe provision of a process for the industrial manufacturing an aqueousdispersion which:

-   -   has a filtration residue below 4 weight-% of the total weight of        the dispersion when filtering the dispersion over 2 g Hyflo        Super Cel® on a filter paper (Whatman 1001-070, Grade 1, median        pore size of 7.0 μm), and    -   can be converted into a water-dispersible powder by        spray-drying, and/or    -   which has a high content of at least one fat-soluble compound        (e.g. a fat-soluble colorant).

SUMMARY OF THE INVENTION

The present invention relates to a powder which contains at least onefat-soluble compound. The powder is preferably water-dispersible andpreferably contains high amount of at least one fat-soluble compound.

To manufacture the powder of the invention, an aqueous dispersion isspray-dried. To achieve a high-quality powder, the dispersion to bespray-dried must a have low filter residue when being filtering over 2 gHyflo Super Cel® on a filter paper (Whatman 1001-070, Grade 1, medianpore size of 7.0 μm).

The dispersion to be spray-dried is obtained by removing the solvent ofan intermediate composition in an evaporator. Said intermediatecomposition comprises water and particles,

wherein said particles have a core and a shell, and

wherein said shell comprises at least one emulsifier, and

wherein said core comprises at least one fat-soluble compound andsolvent,

-   -   characterized in that the particle-solvent-distribution of the        particles in the composition is bimodal.

The emulsifier of the invention is preferably a polymer and even morepreferably a colloid such as a hydrocolloid. Most preferably, theemulsifier of the invention is modified starch (such as modified foodstarch) or gelatin (such as fish gelatin). The most preferred modifiedfood starch is octenyl-succinate starch.

The intermediate composition of the invention may comprise one type ofsolvent only or a mixture of distinct types of solvents. The purpose ofthe evaporation step is the removal of the solvent(s) from theparticle's core. During the evaporation of the solvent, only a fractionof the dispersion's water, related to the applicable VLE data (vaporliquid equilibrium), is evaporated. Thus, the obtained dispersion isliquid. In the context of the present invention, water is not consideredas a solvent.

In a preferred embodiment of the invention, the fat-soluble compound issolid at a temperature of 25° C. An example of such a compound isbeta-carotene. When using such compound, the particle's core may furthercomprise at least one oil, such as vegetable oil. Oil is not removedduring the evaporation step and thus, oil is not considered as asolvent.

The present invention also relates to the industrial manufacturing ofthe dispersion to be spray-dried. For this purpose, a suitable set-up isdisclosed. The set-up of the present invention is a set-up forspray-drying a dispersion. Thus, the set-up of the present inventioncomprises preferably also an apparatus for spray-drying such as aspray-drying tower.

The set-up of the invention comprises evaporator (1), mixing unit (2),vessel (3), vessel (4) and mixing unit (5),

-   -   wherein evaporator (1) has a feed inlet (1 a), a vapor outlet (1        b) and a liquid outlet (1 c), and    -   wherein evaporator (1), mixing unit (2), vessel (3) and mixing        unit (5) are arranged such that a liquid composition can be fed        from vessel (3) into mixing unit (2) and from mixing unit (2)        into evaporator (1) through feed inlet (1 a) of evaporator (1)        and from evaporator (1) through liquid outlet (1 c) of        evaporator (1) into mixing unit (5),    -   characterized in that vessel (4) is arranged such that a liquid        composition can be fed from vessel (4) into mixing unit (2) and        into mixing unit (5).

FIGURES

FIG. 1 is a scheme of the process used in the comparative examples. Itis a linear process with one evaporation step only. The evaporation stepis done to remove the solvent.

FIG. 2 illustrates the drawback of the process used in the comparativeexamples: The attempt to increase the amount of fat-soluble compound(which also requires a larger amount of solvent to solve the fat-solublecompound) fails because the particle collapses at the latest during theevaporation step. In FIG. 2, the particle is shown within an aqueousphase of a liquid composition. Said liquid composition is located in anopen container. The fat-soluble compound (pentagon), the oil (triangle)and the solvent (ellipse) are encapsulated by a shell (circle; dashedline). The shell comprises the emulsifier.

FIG. 3 illustrates the concept of the “critical emulsification massratio”, using a hypothetical system which has a critical emulsificationmass ratio of 0.55. When the relative amount of solvent/fat-solublecompound is increased, the system's critical emulsification mass ratiois eventually exceeded. If the critical emulsification ratio of thesystem is exceeded, filter residue becomes unacceptable high afterremoval of the solvent. In the chosen hypothetical system, there is nooil, i.e. the lipophilic compounds are the solvent and the fat-solublecompound. The hydrophilic matrix of the chosen hypothetical systemconsists of water and emulsifier, i.e. the hydrophilic matrix does notcontain further optional compounds.

FIG. 4 is a graphical illustration of the general principal underlyingthe present invention. It illustrates how the filter residue can be keptlow even if the system has a high content of fat-soluble compounds. Theremoval of the solvent is done in more than one step, i.e. there is morethan one evaporation step (compare with FIG. 1). Furthermore, anintermediate composition is produced which does not occur in the processshown in FIG. 1.

FIG. 5 illustrates why particles do not collapse when using the processof the present invention. In contrast with the process shown in FIG. 2,the formation of particles with a large amount of solvent in the core isavoided when the emulsification step is split into multiple steps thatare separated by evaporation steps.

FIGS. 6 to 8 are illustrations of different embodiments of the set-up ofthe invention.

FIG. 6 shows a preferred embodiment of the invention's set-up, havingtwo evaporators and two mixing units. Evaporator (1) has a feed inlet (1a), a vapor outlet (1 b) and a liquid outlet (1 c). Similarly,evaporator (6) has a feed inlet (6 a), a vapor outlet (6 b) and a liquidoutlet (6 c). Liquid outlet (6 c) may be connected to an apparatus forspray-drying (not shown in FIG. 6). Mixing unit (2) and mixing unit (5)are preferably homogenizers. Mixing unit (2) has inlet (2 a) and outlet(2 b). Similarly, mixing unit (5) has inlet (5 a) and outlet (5 b). Theset-up shown in FIG. 6 further comprises vessel (3) and vessel (4). Inthe embodiment of FIG. 6, evaporator (1), mixing unit (2), vessel (3),mixing unit (5) and evaporator (6) are arranged such that a liquidcomposition can be fed from vessel (3) into mixing unit (2) and frommixing unit (2) into evaporator (1) through feed inlet (1 a) ofevaporator (1) and from evaporator (1) through liquid outlet (1 c) ofevaporator (1) into mixing unit (5) and from mixing unit (5) intoevaporator (6) through feed inlet (6 a) of evaporator (6). Vessel (4) isarranged such that a liquid composition can be fed from vessel (4) intoboth mixing units, i.e. into mixing unit (2) and into mixing unit (5).Vessel (4) is connected to mixing unit (5) by connection (4 a).Connection (4 a) may be a tube, a pipe, a channel, a funnel, a course, aconduit or a duct. The set-up shown in FIG. 6 comprises means to controlthe flow from vessel (4) into mixing unit (2) and into mixing unit (5).Said means may be pumps.

FIG. 7 shows an even more preferred embodiment of the invention'sset-up, having three evaporators and three mixing units. Thus, theset-up shown in FIG. 7 is an extended version of the set-up shown inFIG. 6. Similar to evaporator (1) and evaporator (6), evaporator (8) hasa feed inlet (8 a), a vapor outlet (8 b) and a liquid outlet (8 c).Mixing unit (7) has inlet (7 a) and outlet (7 b), similar to mixing unit(5) and mixing unit (2). The set-up shown in FIG. 7 comprises vessel (3)and vessel (4), similar to the embodiment shown in FIG. 6. In theembodiment of FIG. 7, evaporator (1), mixing unit (2), vessel (3),mixing unit (5), evaporator (6), mixing unit (7) and evaporator (8) arearranged such that a liquid composition can be fed from vessel (3) intomixing unit (2) and from mixing unit (2) into evaporator (1) throughfeed inlet (1 a) of evaporator (1) and from evaporator (1) throughliquid outlet (1 c) of evaporator (1) into mixing unit (5) and frommixing unit (5) into evaporator (6) through feed inlet (6 a) ofevaporator (6) and from evaporator (6) through liquid outlet (6 c) ofevaporator (6) into mixing unit (7) and from mixing unit (7) intoevaporator (8) through feed inlet (8 a) of evaporator (8). Vessel (4) isarranged such that a liquid composition can be fed from vessel (4) intoall three mixing units, i.e. into mixing unit (2), into mixing unit (5)and into mixing unit (7).

Vessel (4) is connected to mixing unit (5) by connection (4 a) and isconnected to mixing unit (7) by connection (4 b). Connection (4 a) andconnection (4 b) may be a tube, a pipe, a channel, a funnel, a course, aconduit or a duct. The set-up shown in FIG. 7 comprises means to controlthe flow from vessel (4) into mixing unit (2), into mixing unit (5) andinto mixing unit (7). Said means may be pumps.

FIG. 8 shows a less preferred embodiment of the embodiment shown in FIG.7. It has also three evaporators and three mixing units. However,instead of vessel (4), the embodiment shown in FIG. 8 has three separatevessels: vessel (4′), vessel (4″) and vessel (4′″). Vessel (4′) isarranged such that a liquid composition can be fed from vessel (4′) intomixing unit (2). Vessel (4″) is arranged such that a liquid compositioncan be fed from vessel (4″) into mixing unit (5). Vessel (4′″) isarranged such that a liquid composition can be fed from vessel (4′″)into mixing unit (7). Vessel (4″) is connected to mixing unit (5) byconnection (4 a) and vessel (4′″) is connected to mixing unit (7) byconnection (4 b). Connection (4 a) and connection (4 b) may be a tube, apipe, a channel, a funnel, a course, a conduit or a duct. The set-upshown in FIG. 8 comprises means to control the flow from vessel (4′)into mixing unit (2), means to control the flow from vessel (4″) intomixing unit (5) and means to control the flow from vessel (4′″) intomixing unit (7). Said means may be pumps.

In FIGS. 7 and 8, liquid outlet (8 c) may be connected to an apparatusfor spray-drying (not shown in FIGS. 7 and 8).

FIG. 9 illustrates the meaning of “bimodal”. When running the process ofthe invention, a composition inevitably occurs that comprises two typesof particles: some particles comprise many solvent molecules in the core(i.e. mode 1) whereas the other particles comprise none or few solventmolecules in the core (mode 2). A mixture of two different unimodaldistributions (i.e. distributions having only one mode) give raise to abimodal distribution.

It is to be understood that the figures are meant for illustrativepurposes only. The person skilled in the art understands that realitymay be more complex.

Furthermore, it is to be understood that the figures are not limitingthe scope of the invention. FIGS. 2 and 5, for example, show systemswhich include oil. However, oil is an optional component (vide infra).This applies mutatis mutandis to the other features shown in thefigures, too.

DETAILED DESCRIPTION OF THE INVENTION

Powders can be obtained e.g. by spray-drying an aqueous dispersion whichcomprises particles. Other processes to convert aqueous dispersions intoa powder are also known.

In the process of the prior art, the dispersion to be spray-dried isobtained by removing solvent from an emulsion (cf. FIG. 1). If theemulsification mass ratio of the emulsion is too high, the dispersion tobe spray-dried has poor quality. Poor quality can mean that the obtainedspray-dried powder is not fully water-dispersible, i.e. parts of thepower float or sediment in an beverage. Therefore, powders comprising avery large amount of at least one fat-soluble compound are difficult oreven impossible to manufacture when using the solvent process of theprior art.

In the process of the present invention, the dispersion to bespray-dried is obtained by removing solvent from a specific composition(herein after referred to as “intermediate composition”; cf. FIGS. 4 and5). Surprisingly, the thus obtained dispersion has excellent qualityeven if the intermediate composition is highly concentrated. Therefore,it is possible to manufacture powders and/or dispersion that comprise alarge amount of at least one fat-soluble compound even if alow-performing solvent such as ethyl acetate or isopropyl acetate isused. Low-performing means that a relatively large amount of the solventat relative high temperature is needed for solving fat-soluble colorantssuch as beta-carotene or lycopene. Advantages of ethyl acetate andisopropyl acetate are lower cost and increased safety andsustainability.

Limitations of the Process of the Prior Art

The process used in the comparative examples is shown in FIGS. 1 and 2.The cores of the emulsion's particles comprise solvent. When theemulsion is heated in an evaporator, the solvent escapes/is removed fromthe particle's core, i.e. the volume of the core is reduced. Thus, theparticles become smaller when the solvent is removed.

The process of the prior art fails when highly concentrated emulsionsare used.

While not wishing to be bound by any particular theory or mechanism, itis believed that particles collapse in the emulsification step or in theevaporator when the particle's core comprises too much solvent, i.e.when the inner phase is too large.

Small amounts of solvent can get through the particle's shell as theshell is somewhat flexible: emulsifier molecules forming the core'sshell drift temporarily apart to let solvent molecules through.Unfortunately, this mechanism does not work when too many solventmolecules are trying get through the particle's shell at the same momentin time: it makes the particle explode/collapse. The remains of thecollapsed particles then agglutinate or agglomerate. As a result, thefilter residue increases to an unacceptable high level when thedispersion is filtered after the evaporation step. This postulatedmechanism is illustrated in FIG. 2.

Particles collapse in the emulsification step or in the evaporation stepwhen the critical emulsification mass ratio of the chosen system isexceeded. The critical emulsification mass ratio is relatively soonexceeded when using the process of the prior art. This is illustrated inFIG. 3, using a hypothetical exemplary system.

Inventive Concept

The process of the invention is shown in FIG. 4: the emulsification stepand the evaporation step are split up in multiple steps. As a result,particles with a large amount of solvent in their core are not formedduring the process.

Thereof, particles do not collapse in the emulsification or evaporationstep. This mechanism is illustrated in FIG. 5: only a part of thelipophilic compounds is emulsified. During emulsification, particles areformed which contain a relatively small amount of solvent in theirscore. Said small amount solvent can be removed by evaporation withoutmaking particles collapse. A second part of the lipophilic compounds isthen emulsified. Then, solvent from the core of the newly formedparticles is removed by evaporation. The old particles are stable enoughto survive a second emulsification/evaporation step. When using theset-up of the invention, it can be controlled how many times an oldparticle must go through a further emulsification/evaporation step. Inthe set-up shown in FIGS. 7 and 8, the particles formed in mixing unit(2)/evaporator (1) must survive two further emulsification/evaporationsteps whereas the particles formed in mixing unit (5)/evaporator (6)must survive one further emulsification/evaporation step only.

Because particles do not collapse when using the process of theinvention, highly concentrated dispersions of fat-soluble compounds withexcellent quality can be manufactured. And if a highly concentrateddispersion is spray-dried, a highly concentrated powder is obtained.

In the process of the invention, the emulsification step and theevaporation step are done at least twice. It is therefore possible, torun the process of the invention in a circular manner. If the process isrun in a circular manner, it cannot be excluded that some of theparticles must survive significantly more than two furtheremulsification/evaporation steps. Thus, using a set-up with multiplemixing-units/evaporators is a approach which is al lot moregentle/milder.

Definitions

In the context of the present invention, a “dispersion” may be anemulsion, i.e. the particle's core may be liquid. Alternatively, thedispersion may be a suspension, i.e. the particle's core may be solid.In a typical embodiment of the present invention, however, theparticle's core of the dispersion comprises both, liquid and solidcompounds.

The “particles” of dispersion are too small to be seen with the nakedeye. In a preferred embodiment of the invention, the particles have anaverage size in the range from 50 to 1000 nm, more preferably from 100to 800 nm and more preferably from 100 to 500 nm [mean size by cumulant,measured by Photo Correlation Spectroscopy (Beckman Coulter N4 PlusSubmicron Particle Sizer)]. “Mean size by cumulant” refers to thez-average, preferably determined according to ISO22412:2008. Theparticles are water-dispersible despite of having a lipophilic core.This is achieved by surrounding the core with an emulsifier. Saidsurrounding is referred to as the shell of the particle. The core of theparticles may or may not comprise solvent. If it comprises solvent, itmay be one solvent only or a mixture of multiple solvents.

The “solvent” of the invention is an organic solvent which haspreferably a boiling point of less than 120° C., more preferably lessthan 100° C. at 1013.25 hPa. Any organic solvent that is mentioned in EP0 937 412 can be used as long as the chosen fat-soluble compound can beat least partially solved in it. Preferred solvents are water-immiscibleor miscible organic solvent such as dimethyl carbonate, ethyl formate,ethyl or isopropyl acetate, methyl tert-butyl ether and methylenechloride, wherein isopropyl acetate and ethyl acetate are particularlypreferred. In the context of the present invention, oils are notconsidered as solvents. Typically, oils have a boiling point of morethan 120° C. at 1013.25 hPa. In the context of the present invention,water is not considered as solvent either.

A distribution function for a particular property defines quantitativelyhow the values of that property are distributed among the particles inthe entire population. In the context of the present invention, therelevant property is the number of solvent molecules in the particle'score. Thus, in the context of the present invention,“particle-solvent-distribution” indicates the number of particlespresent according to the number of solvent molecules in the core. Theparticle-solvent-distribution function P(S) is defined by P(S)=number ofparticles in the population having S solvent molecules in the core,wherein the symbol S is a non-negative integer (i.e.

₀={0;1;2;3;4; . . . }). “Bimodal” means that two distinct peaks (localmaxima) appear in the smoothed particle-solvent-distribution functionP(S) as illustrated in FIG. 9. The person skilled in the art is familiarwith “smoothing”. Smoothing allows to capture important patterns in thedata, while leaving out noise or other fine-scale structures. Thus, as arough approximation, bimodal means that there are two types ofparticles: some particles comprise many solvent molecules in the corewhereas the other particles comprise none or few solvent molecules inthe core.

The “intermediate composition” of the invention is a composition,comprising water and particles,

wherein said particles have a core and a shell, and

wherein said shell comprises at least one emulsifier, and

wherein said core comprises at least one fat-soluble compound andsolvent,

-   -   characterized in that the particle-solvent-distribution of the        particles in the composition is bimodal.

Thus, roughly speaking, the intermediate composition comprises two typesof particles, wherein the two types of particles differ from one anotherby the amount of solvent in the core. In a preferred embodiment of theinvention, the core of one type of particles of the intermediatecomposition are essentially free of solvent whereas the core of theother type of particles of the intermediate composition contain asignificant number of solvent molecules. The expression “core beingessentially free of solvent” refers to a particle that comprises lessthan 10'000 ppm, preferably less than 100 ppm and most preferably lessthan 10 ppm solvent molecules in its core (ppm=mol fraction). Theexpression “significant number of solvent molecules” refers preferablyto at least 5% solvent molecules, more preferably to at least 40%solvent molecules and most preferably to at least 85% solvent molecules,based on the total number of molecules in the core of the particle.

Fat-soluble compounds are understood to have a solubility in water ofless than 5 g fat-soluble compound/L water at 20° C., preferably of lessthan 2 g fat-soluble compound/L water at 20° C., and most preferably ofless than 1 g fat-soluble compound/L water at 20° C. Preferred“fat-soluble compounds” are fat-soluble colorants or fat-solublemicronutrients such as fat-soluble vitamins and fatty acids. In a morepreferred embodiment of the invention, fat-soluble compounds arecarotenoids, retinoids and natural colorants being mentioned inparagraph [0015] of EP 0 937 412 B1. In an even more preferredembodiment of the invention, fat-soluble compounds are beta-carotene,lycopene, beta-apo-4′-carotenal, beta-apo-8′-carotenal,beta-apo-12′-carotenal, beta-apo-8′-carotenic acid, astaxanthin,canthaxanthin, zeaxanthin cryptoxanthin, citranaxanthin, lutein,torularodin-aldehyde, torularodin-ethylester,neurosporaxanthin-ethylester, zeta-carotene or dehydroplectaniaxanthin.In the most preferred embodiment of the invention, fat-soluble compoundsare beta-carotene or lycopene.

Thus, one embodiment of the invention relates to a composition,comprising water and particles,

wherein said particles have a core and a shell, and

wherein said shell comprises at least one emulsifier, and

wherein said core comprises at least one fat-soluble compound andsolvent,

-   -   characterized in that the particle-solvent-distribution of the        particles in the composition is bimodal, and    -   characterized in that said at least one fat-soluble compound is        a carotenoid, retinoid and/or a colorant, and/or wherein said at        least one fat-soluble compound is preferably beta-carotene,        lycopene, beta-apo-4′-carotenal, beta-apo-8′-carotenal,        beta-apo-12′-carotenal, beta-apo-8′-carotenic acid, astaxanthin,        canthaxanthin, zeaxanthin cryptoxanthin, citranaxanthin, lutein,        torularodin-aldehyde, torularodin-ethylester,        neurosporaxanthin-ethylester, zeta-carotene,        dehydroplectaniaxanthin, bixin, saffron, crocin, capsanthin,        capsorubin, rubixanthin, violaxanthin and/or rhodoxanthin, a        metal chelate of carminic acid, curcumin and/or chlorophyllin.

In the context of the present invention, the term “lipophilic compounds”refers to (a) the at least one fat-soluble compound, (b) the solvent(s)and (c) the optionally oil. The lipophilic compounds are supplied byvessel (4) of the set-up of the invention (vide infra). The term“hydrophilic matrix” refers to (1) the water, (2) the at least oneemulsifier and (3) to further water-soluble compounds which areoptionally present such as sugar.

In the context of the present invention, the “emulsification mass ratio”relates to a composition comprising (i) lipophilic compounds(=fat-soluble compounds, solvent and optionally oil) and (ii)hydrophilic matrix and is calculated as follows:

$\frac{{total}\mspace{14mu} {mass}\mspace{14mu} {of}{\mspace{11mu} \;}{all}\mspace{14mu} {lipophilic}\mspace{14mu} {compounds}}{{total}\mspace{14mu} {mass}\mspace{14mu} {of}\mspace{14mu} {the}\mspace{14mu} {composition}}$

Alternatively, the emulsification mass ratio can be expressed inpercentages:

$\frac{{total}\mspace{14mu} {mass}\mspace{14mu} {of}{\mspace{11mu} \;}{all}\mspace{14mu} {lipophilic}\mspace{14mu} {compounds}*100}{{total}\mspace{14mu} {mass}\mspace{14mu} {of}\mspace{14mu} {the}\mspace{14mu} {composition}}$

When filtering the dispersion after removal of the solvent (and partialremoval of the water, depending on the applicable vapor liquidequilibrium), the filter residue increases dramatically if the relativeamount of the lipophilic compounds in the respective dispersion exceedsa certain threshold. In the context of the present invention, thisthreshold is referred to as “critical emulsification mass ratio” (cf.FIG. 3 for a hypothetical example). The value of a system's criticalemulsification mass ratio depends on the chosen solvent, fat-solublecompound and emulsifier. For systems comprising ethyl acetate orisopropyl acetate, it is lower than for a corresponding systemcomprising a high-performing solvent such as methylene chloride.

Any of the colloids mentioned in paragraph [0021] of EP 0 937 412 B1 canbe used as emulsifier. However, preferred emulsifiers of the inventionare modified starch and gelatin. A particularly preferred modifiedstarch is octenyl-succinate starch (“OSA starch”), preferably as definedin WO 2013/144221. OSA starch is commercially available e.g. under thebrand HiCap® or Capsul®. Less preferred emulsifiers are colloids such asxanthan gum, gum arabic, guar gum, locust bean gum, carboxymethylcellulose and alginate.

A “set-up” is a way in which things are arranged. In a preferredembodiment of the invention, the set-up is an apparatus. Said apparatusmay be part of a plant which comprises other equipment such as aspray-drying tower.

In the context of the present invention, the expressions “weight” of acomposition and “mass” of a composition are used interchangeably.

Method of Manufacturing the Dispersion

The method used in the comparative examples is shown in FIG. 1. It is alinear process, i.e. everything is emulsified in one step before removalof the solvent. In this process, the mass ratio of the two compositionsmust be chosen such that the critical emulsification mass ratio is notexceeded (cf. hypothetical example of FIG. 3).

In contrast, the method of the invention is an iterative process: thesolution comprising the solvent and the at least one fat-solublecompound is added stepwise and thus, the critical emulsification massratio of the system is never exceeded. In between the steps, the solventis removed by evaporation. When the solvent is removed in an evaporator(preferably at a pressure of less than 1500 mbar, preferably at apressure of less than 1000 mbar), a small amount of water (e.g. lessthan 1 weight-% of the composition's water) also evaporates. Thecomplete removal of the solvent is desired but not absolutely benecessary, i.e. it might be sufficient to remove 95%, preferably 98% andmost preferably 99% of the solvent molecules that are contained in therespective composition. The thus obtained composition might contain1000-15000 ppm or less solvent. To further reduce the amount of solvent(e.g. to a residual solvent level of below 10 ppm), an additionalevaporation step can be applied (not shown in the figures).

The general principle of the present invention is shown in FIG. 4. Thus,the present invention relates to a process for the preparation of apowder comprising at least one fat-soluble compound, wherein the processcomprises the steps of

-   -   a) providing a solution comprising at least one fat-soluble        compound, at least one solvent and optionally at least one oil,    -   b) providing a composition comprising water and at least one        emulsifier    -   c) rapidly mixing a fraction of the solution of step a) at a        temperature in the range of 20-100° C. with a fraction of the        solution of step b),    -   d) removing said at least one solvent by heating the composition        of step c)    -   e) adding additional fractions of compositions of step a) and        optionally step b) to the composition of step d) under vigorous        stirring,    -   f) removing the solvent, preferably by heating the composition        of step e) at a pressure of less than 1500 mbar.

In step e) of this process, the intermediate composition of theinvention is obtained.

The present invention also relates to a process comprising the steps of

-   -   a) providing a solution comprising at least one fat-soluble        compound, at least one solvent and optionally at least one oil,    -   b) providing a composition comprising water and at least one        emulsifier    -   c) rapidly mixing a fraction of the solution of step a) at a        temperature in the range of 20-100° C. with a fraction of the        solution of step b),    -   d) removing said at least one solvent by heating the composition        of step c)    -   e) adding additional fractions of compositions of step a) and        optionally step b) to the composition of step d) under vigorous        stirring,    -   f) removing the solvent, preferably by heating the composition        of step e) at a pressure of less than 1500 mbar    -   g) adding an additional fraction of composition of step a) to        the composition of step f) under vigorous stirring, and    -   h) removing said solvent at least partially by heating the        composition of step g) at a pressure of less than 1500 mbar.

In step e) and in step g) of this process, the intermediate compositionof the invention is obtained. Thus, the present invention also relatesto a process comprising the following steps:

-   -   a) providing a composition comprising water and particles,        wherein said particles have a core and a shell, and wherein said        shell comprises at least one emulsifier, and wherein said core        comprises at least one fat-soluble compound and at least one        solvent, characterized in that the particle-solvent-distribution        of the particles in the composition is bimodal    -   b) removing the organic solvent at least partially, preferably        by heating the composition of step a) at a pressure of        preferably less than 1500 mbar    -   c) optionally converting the dispersion of step b) into a        powder.

In a preferred embodiment of the invention, the intermediate compositionof the invention comprises water and particles,

-   -   wherein said particles have a core and a shell, and    -   wherein said shell comprises at least one modified starch and/or        or at least one gelatin, and    -   wherein said core comprises at least one colorant, at least one        solvent and optionally at least one edible oil, and wherein said        at least one colorant is preferably beta-carotene and/or        lycopene, and wherein said at least one solvent is preferably        ethyl acetate and/or isopropyl acetate, and wherein said at        least one edible oil is preferably corn oil,    -   characterized in that the particle-solvent-distribution of the        particles in the composition is bimodal.

Thus, a preferred embodiment of the invention relates to a processcomprising the steps:

-   -   a) providing a composition comprising water and particles,        wherein said particles have a core and a shell, and wherein said        shell comprises at least one modified starch and/or at least one        gelatin, and wherein said core comprises at least one colorant,        at least one solvent and optionally at least one edible oil, and        wherein said at least one colorant is preferably beta-carotene        and/or lycopene, and wherein said at least one solvent is        preferably ethyl acetate and/or isopropyl acetate, and wherein        said at least one edible oil is preferably corn oil, and        characterized in that the particle-solvent-distribution of the        particles in the composition is bimodal,    -   b) removing the organic solvent at least partially, preferably        by heating the composition of step a), and    -   c) optionally converting the dispersion of step b) into a        powder.

The intermediate composition may have a relatively high emulsificationratio because a fraction of the fat-soluble compound and the optional atleast one oil is enclosed in particles which are already free ofsolvent. In a preferred embodiment of the invention at least 10%,preferably at least 20% and most preferably at least 30% of theintermediate composition's particles have a core which is essentiallyfree of solvent.

The value of the acceptable emulsification ratio of the intermediatecomposition depends on the chosen system. Below list gives an overviewof preferred embodiments of the invention's intermediate composition:

Intermediate composition comprising . . . . . . and particles, whereinsaid particles have . . . and . . . . . . a core . . . a shellemulsification ratio of the . . . water comprising comprisingintermediate composition beta-carotene, at least one from 5% to 25%,preferably edible oil and ethyl modified from 5% to 20% and most acetatestarch preferably from 5% to 15% beta-carotene, at least one from 5% to60%, preferably edible oil and ethyl gelatin from 5% to 50% and mostacetate preferably from 5% to 40% beta-carotene, at least one from 5% to55%, preferably edible oil and modified from 5% to 50% and mostisopropyl acetate starch preferably from 5% to 40% beta-carotene, atleast one from 5% to 60%, preferably edible oil and gelatin from 5% to55% and most isopropyl acetate preferably from 5% to 45% lycopene,edible at least one from 5% to 40%, preferably oil and ethyl modifiedfrom 5% to 30% and most acetate starch preferably from 5% to 20%lycopene, edible at least one from 5% to 60%, preferably oil and ethylgelatin from 5% to 50% and most acetate preferably from 5% to 40%lycopene, edible at least one from 5% to 60%, preferably oil andisopropyl modified from 5% to 50% and most acetate starch preferablyfrom 5% to 40% lycopene, edible at least one from 5% to 35%, preferablyoil and isopropyl gelatin from 5% to 30% and most acetate preferablyfrom 5% to 25%

Spray-Dried Powder

The spray-dried powder of the invention is water-dispersible andcomprises a high content of at least one fat-soluble compound. “High”means that the same content of the same fat-soluble compound cannot beachieved for the same system/solvent when the manufacturing process ofthe prior art is used. The exact value of “high” depends on the chosensystem/solvent. Highest content can be achieved if methylene chloride isused as solvent and/or if gelatine is used as emulsifier, provided themanufacturing process of the invention is used. Below list gives anoverview of preferred embodiments of the invention's spray-dried powder.In these preferred embodiments, a colloid is used as emulsifier, whereinOSA-starch is the preferred modified starch and wherein fish gelatin isthe preferred gelatin:

amount of fat-soluble compound, based on the total weight of the PowderFat-soluble oil spray-dried # compound (yes/no) emulsifier composition 1beta-carotene yes at least one at least 10 weight-%, modified preferablyat least 20 starch weight-% 2 beta-carotene yes at least one at least 15weight-%, gelatin preferably at least 35 weight-% 3 lycopene no at leastone at least 15 weight-%, modified preferably at least 25 starchweight-% 4 lycopene no at least one at least 15 weight-%, gelatinpreferably at least 40 weight-%

Set-Up

The present invention also relates to a set-up, i.e. to a way in whichthings are arranged. In a preferred embodiment, the set-up of thepresent invention is an apparatus.

When using the process of the invention, the set-up of the invention ispreferably used. The process of the invention requires at least twoemulsification steps. Therefore, the set-up of the invention comprisesat least two mixing units (cf. mixing units (2) and (5) in FIG. 6). In apreferred embodiment, the set-up of the invention comprises at leastthree mixing units (cf. mixing units (2), (5) and (7) in FIGS. 7 and 8).

Typically, the process of the invention also requires at least twoevaporation steps. Thus, the set-up of the invention comprisespreferably at least two evaporators (cf. evaporators (1) and (6) in FIG.6). In a preferred embodiment, the set-up of the invention comprises atleast three evaporators (cf. evaporators (1), (6) and (8) in FIGS. 7 and8).

The set-up of the invention is used for encapsulating fat-solublecompounds with at least one emulsifier, wherein said at least oneemulsifier is preferably a colloid. By encapsulating a fat-solublecompound, the fat-soluble compound becomes water-dispersible. Onceencapsulation is done, spray-drying may begin. Thus, the set-up of theinvention may optionally also comprise at least one apparatus forspray-drying (not shown in the figures).

The set-up of the invention comprises evaporator (1), mixing unit (2),vessel (3), vessel (4) and mixing unit (5),

wherein evaporator (1) has a feed inlet (1 a), a vapor outlet (1 b) anda liquid outlet (1 c), and

-   -   wherein evaporator (1), mixing unit (2), vessel (3) and mixing        unit (5) are arranged such that a liquid composition can be fed        from vessel (3) into mixing unit (2) and from mixing unit (2)        into evaporator (1) through feed inlet (1 a) of evaporator (1)        and from evaporator (1) through liquid outlet (1 c) of        evaporator (1) into mixing unit (5),    -   characterized in that vessel (4) is arranged such that a liquid        composition can be fed from vessel (4) into mixing unit (2) and        into mixing unit (5), wherein vessel (4) is preferably connected        to mixing unit (5) by connection (4 a), and wherein said        connection (4 a) is preferably a tube, a pipe, a channel, a        funnel, a course, a conduit or a duct.

In a preferred embodiment, the set-up of the invention comprisesevaporator (1), mixing unit (2), vessel (3), mixing unit (5) andevaporator (6),

-   -   wherein evaporator (1) has a feed inlet (1 a), a vapor outlet (1        b) and a liquid outlet (1 c), and    -   wherein evaporator (6) has a feed inlet (6 a), a vapor outlet (6        b) and a liquid outlet (6 c), and    -   wherein evaporator (1), mixing unit (2), vessel (3), mixing unit        (5) and evaporator (6) are arranged such that a liquid        composition can be fed from vessel (3) into mixing unit (2), and        from mixing unit (2) into evaporator (1) through feed inlet (1        a) of evaporator (1) and from evaporator (1) through liquid        outlet (1 c) of evaporator (1) into mixing unit (5), and from        mixing unit (5) into evaporator (6) through feed inlet (6 a) of        evaporator (6),    -   characterized in that vessel (4) is arranged such that a liquid        composition can be fed from vessel (4) into mixing unit (2) and        into mixing unit (5), wherein vessel (4) is preferably connected        to mixing unit (5) by connection (4 a), and wherein said        connection (4 a) is preferably a tube, a pipe, a channel, a        funnel, a course, a conduit or a duct.

In the even more preferred embodiment, the set-up of the inventioncomprises evaporator (1), mixing unit (2), vessel (3), mixing unit (5),evaporator (6), mixing unit (7) and evaporator (8)

-   -   wherein evaporator (1) has a feed inlet (1 a), a vapor outlet (1        b) and a liquid outlet (1 c), and    -   wherein evaporator (6) has a feed inlet (6 a), a vapor outlet (6        b) and a liquid outlet (6 c), and    -   wherein evaporator (8) has a feed inlet (8 a), a vapor outlet (8        b) and a liquid outlet (8 c), and    -   wherein evaporator (1), mixing unit (2), vessel (3), mixing unit        (5), evaporator (6), mixing unit (7) and evaporator (8) are        arranged such that a liquid composition can be fed from vessel        (3) into mixing unit (2), and from mixing unit (2) into        evaporator (1) through feed inlet (1 a) of evaporator (1) and        from evaporator (1) through liquid outlet (1 c) of evaporator        (1) into mixing unit (5), and from mixing unit (5) into        evaporator (6) through feed inlet (6 a) of evaporator (6), and        from evaporator (6) through liquid outlet (6 c) of evaporator        (6) into mixing unit (7) and from mixing unit (7) into        evaporator (8) through feed inlet (8 a) of evaporator (8),    -   characterized in that vessel (4) is arranged such that a liquid        composition can be fed from vessel (4) into mixing unit (2) and        into mixing unit (5),    -   wherein vessel (4) is preferably connected to mixing unit (5) by        connection (4 a), and/or    -   wherein vessel (4) is preferably connected to mixing unit (7) by        connection (4 b), and    -   wherein said connection (4 a) and/or connection (4 b) is        preferably a tube, a pipe, a channel, a funnel, a course, a        conduit or a duct.

Preferably, the set-up of the invention is suitable to manufacturepowder at industrial scale, i.e. to manufacture large quantities ofpowder. Therefore, vessel (3) and/or vessel (4) is preferably capable ofholding a volume of at least 100 liters, more preferably of at least 500liters and most preferably of at least 3000 liters. For the same reason,connection (4 a) and/or connection (4 b) has preferably a length of atleast 2 meters, more preferably of at least 10 meters and mostpreferably of at least 100 meters. Typically, connection (4 a) isconnected to inlet (5 a) of mixing unit (5). Similarly, connection (4 b)is typically connected to inlet (7 a) of mixing unit (7).

Typically, the flow rate from vessel (4) into mixing unit (2), intomixing unit (5) and/or into mixing unit (7) needs to be adjustable.Therefore, the set-up of the present invention comprises preferablymeans to control the flow from vessel (4) into mixing unit (2), intomixing unit (5) and/or into mixing unit (7). Said means may be a pump.

Typically, the flow rate from vessel (3) into mixing unit (2) needs tobe adjustable, too. Therefore, the set-up of the present inventioncomprises preferably means to control the flow from vessel (3) intomixing unit (2), wherein vessel (3) is preferably provided with a pumpto control the flow from vessel (3) into mixing unit (2).

Therefore, a preferred embodiment of the present invention relates to aset-up that comprises evaporator (1), mixing unit (2), vessel (3),vessel (4) and mixing unit (5),

wherein evaporator (1) has a feed inlet (1 a), a vapor outlet (1 b) anda liquid outlet (1 c), and

-   -   wherein evaporator (1), mixing unit (2), vessel (3) and mixing        unit (5) are arranged such that a liquid composition can be fed        from vessel (3) into mixing unit (2) and from mixing unit (2)        into evaporator (1) through feed inlet (1 a) of evaporator (1)        and from evaporator (1) through liquid outlet (1 c) of        evaporator (1) into mixing unit (5),    -   wherein vessel (4) is arranged such that a liquid composition        can be fed from vessel (4) into mixing unit (2) and into mixing        unit (5), and    -   wherein the set-up comprises means to control the flow from        vessel (4) into mixing unit (2) and into mixing unit (5), and    -   wherein the set-up preferably comprises a pump to control the        flow from vessel (4) into mixing unit (2) and/or wherein the        set-up preferably comprises a pump to control the flow from        vessel (4) into mixing unit (5), and/or    -   wherein the set-up comprises means to control the flow from        vessel (3) into mixing unit (2), and wherein vessel (3) is        preferably provided with a pump to control the flow from vessel        (3) into mixing unit (2).

In an even more preferred embodiment, the set-up of the inventioncomprises evaporator (1), mixing unit (2), vessel (3), mixing unit (5),evaporator (6), mixing unit (7) and evaporator (8),

-   -   wherein evaporator (1) has a feed inlet (1 a), a vapor outlet (1        b) and a liquid outlet (1 c), and    -   wherein evaporator (6) has a feed inlet (6 a), a vapor outlet (6        b) and a liquid outlet (6 c), and    -   wherein evaporator (8) has a feed inlet (8 a), a vapor outlet (8        b) and a liquid outlet (8 c), and    -   wherein evaporator (1), mixing unit (2), vessel (3), mixing unit        (5) and evaporator (6) are arranged such that a liquid        composition can be fed from vessel (3) into mixing unit (2), and        from mixing unit (2) into evaporator (1) through feed inlet (1        a) of evaporator (1) and from evaporator (1) through liquid        outlet (1 c) of evaporator (1) into mixing unit (5), and from        mixing unit (5) into evaporator (6) through feed inlet (6 a) of        evaporator (6), and from evaporator (6) through liquid outlet (6        c) of evaporator (6) into mixing unit (7) and from mixing unit        (7) into evaporator (8) through feed inlet (8 a) of evaporator        (8),    -   wherein in that vessel (4) is arranged such that a liquid        composition can be fed from vessel (4) into mixing unit (2) and        into mixing unit (5), and    -   wherein the set-up comprises means to control the flow from        vessel (4) into mixing unit (2) and into mixing unit (5), and    -   wherein the set-up preferably comprises a pump to control the        flow from vessel (4) into mixing unit (2), into mixing unit (5)        and/or into mixing unit (7), and/or    -   wherein the set-up comprises means to control the flow from        vessel (3) into mixing unit (2), and wherein vessel (3) is        preferably provided with a pump to control the flow from vessel        (3) into mixing unit (2).

In the above described embodiments, mixing unit (2), mixing unit (5)and/or into mixing unit (7) are suitable for manufacturing an emulsion.To do so, high shear forces are required. Thus, said mixing units arepreferably a homogenizer device such as a high-pressure homogenizer(e.g. with a pressure drop of at least 50 bar, preferably with apressure drop from 200 bar to 500 bar and/or an orifice with a diameterof less than 1000 μm, preferably less than 500 μm and most preferablyless than 300 μm), a colloid mill, a nozzle (e.g. with a nozzle diameterfrom 0.1 mm to 0.5 mm, preferably from 0.2 mm to 0.3 mm), a rotor-statorhomogenizer (e.g. allowing a rotor speed of at least 3000 rpm,preferably of at least 4000 rpm and most preferably of at least 5000rpm; rpm=revolutions per minute) or a combination of the mentionedequipment.

In the above described embodiments, evaporator (1), evaporator (6)and/or evaporator (8) may be a vertical evaporator, a film evaporator, aflash vessel or any other kind of evaporator that can be used to removean organic solvent. In a preferred embodiment, said evaporators are filmevaporators. Most preferably, said evaporators are wiped fine filmevaporators.

When doing the process of the invention, vessel (4) of the set-up holdstypically a solution comprising at least one fat-soluble compound, atleast one solvent and optionally at least one oil. In a less preferredembodiment, said solution is hold by more than one vessel. In such lesspreferred embodiment, the set-up of the invention comprises vessel (4′),vessel (4″) and optionally vessel (4′″).

Thus, the present invention also relates to a set-up comprisingevaporator (1), mixing unit (2), vessel (3), mixing unit (5) andevaporator (6),

-   -   wherein evaporator (1) has a feed inlet (1 a), a vapor outlet (1        b) and a liquid outlet (1 c), and

wherein evaporator (6) has a feed inlet (6 a), a vapor outlet (6 b) anda liquid outlet (6 c), and

-   -   wherein evaporator (1), mixing unit (2), vessel (3), mixing unit        (5) and evaporator (6) are arranged such that a liquid        composition can be fed from vessel (3) into mixing unit (2), and        from mixing unit (2) into evaporator (1) through feed inlet (1        a) of evaporator (1) and from evaporator (1) through liquid        outlet (1 c) of evaporator (1) into mixing unit (5), and from        mixing unit (5) into evaporator (6) through feed inlet (6 a) of        evaporator (6),    -   characterized in that said said-up further comprises vessel (4′)        and vessel (4″), wherein vessel (4′) is arranged such that a        liquid composition can be fed from vessel (4′) into mixing unit        (2), and/or wherein vessel (4″) is arranged such that a liquid        composition can be fed from vessel (4″) into mixing unit (5).

Another less preferred embodiment relates to set-up of the inventioncomprises evaporator (1), mixing unit (2), vessel (3), mixing unit (5),evaporator (6), mixing unit (7) and evaporator (8),

-   -   wherein evaporator (1) has a feed inlet (1 a), a vapor outlet (1        b) and a liquid outlet (1 c), and    -   wherein evaporator (6) has a feed inlet (6 a), a vapor outlet (6        b) and a liquid outlet (6 c), and    -   wherein evaporator (8) has a feed inlet (8 a), a vapor outlet (8        b) and a liquid outlet (8 c), and    -   wherein evaporator (1), mixing unit (2), vessel (3), mixing unit        (5) and evaporator (6) are arranged such that a liquid        composition can be fed from vessel (3) into mixing unit (2), and        from mixing unit (2) into evaporator (1) through feed inlet (1        a) of evaporator (1) and from evaporator (1) through liquid        outlet (1 c) of evaporator (1) into mixing unit (5), and from        mixing unit (5) into evaporator (6) through feed inlet (6 a) of        evaporator (6), and from evaporator (6) through liquid outlet (6        c) of evaporator (6) into mixing unit (7) and from mixing unit        (7) into evaporator (8) through feed inlet (8 a) of evaporator        (8) wherein in that vessel (4) is arranged such that a liquid        composition can be fed from vessel (4) into mixing unit (2) and        into mixing unit (5), and    -   characterized in that said said-up further comprises vessel        (4′), (4″) and vessel (4′″), wherein vessel (4′) is arranged        such that a liquid composition can be fed from vessel (4′) into        mixing unit (2), and/or wherein vessel (4″) is arranged such        that a liquid composition can be fed from vessel (4″) into        mixing unit (5) and/or wherein vessel (4′″) is arranged such        that a liquid composition can be fed from vessel (4′″) into        mixing unit (7).

In a less preferred embodiment of the invention, the set-up of theinvention also comprises an apparatus for spray-drying, such as aspray-drying tower.

Said apparatus might be directly or indirectly connected to the liquidoutlet of one of the evaporators.

Preferred Embodiments

-   1. Use of a set-up for encapsulating a fat-soluble compound, said    set-up comprising evaporator (1), mixing unit (2), vessel (3),    vessel (4) and mixing unit (5),    -   wherein evaporator (1) has a feed inlet (1 a), a vapor outlet (1        b) and a liquid outlet (1 c), and    -   wherein evaporator (1), mixing unit (2), vessel (3) and mixing        unit (5) are arranged such that a liquid composition can be fed        from vessel (3) into mixing unit (2) and from mixing unit (2)        into evaporator (1) through feed inlet (1 a) of evaporator (1)        and from evaporator (1) through liquid outlet (1 c) of        evaporator (1) into mixing unit (5),    -   characterized in that vessel (4) is arranged such that a liquid        composition can be fed from vessel (4) into mixing unit (2) and        into mixing unit (5).-   2. Use according to embodiment 1,    -   wherein the set-up comprises means to control the flow from        vessel (4) into mixing unit (2) and/or into mixing unit (5), and        wherein the set-up preferably comprises a pump to control the        flow from vessel (4) into mixing unit (2) and/or wherein the        set-up preferably comprises a pump to control the flow from        vessel (4) into mixing unit (5), and/or    -   wherein the set-up comprises means to control the flow from        vessel (3) into mixing unit (2), and wherein vessel (3) is        preferably provided with a pump to control the flow from vessel        (3) into mixing unit (2).-   3. Use according to embodiment 1 or 2,    -   wherein vessel (4) is connected to mixing unit (5) by connection        (4 a), wherein said connection (4 a) is preferably a tube, a        pipe, a channel, a funnel, a course, a conduit or a duct, and/or    -   wherein said connection (4 a) has preferably a length of at        least 2 meters, more preferably of at least 10 meters and most        preferably of at least 100 meters.-   4. Use according to embodiment according to any one of the preceding    claims, wherein each of said vessels (3) and (4) is capable of    holding a volume of at least 100 liters, preferably of at least 500    liters and most preferably of at least 3000 liters.-   5. Use of a set-up for encapsulating a fat-soluble compound, said    set-up comprising evaporator (1), mixing unit (2), vessel (3),    mixing unit (5) and evaporator (6),    -   wherein evaporator (1) has a feed inlet (1 a), a vapor outlet (1        b) and a liquid outlet (1 c), and    -   wherein evaporator (6) has a feed inlet (6 a), a vapor outlet (6        b) and a liquid outlet (6 c), and    -   wherein evaporator (1), mixing unit (2), vessel (3), mixing unit        (5) and evaporator (6) are arranged such that a liquid        composition can be fed from vessel (3) into mixing unit (2), and        from mixing unit (2) into evaporator (1) through feed inlet (1        a) of evaporator (1) and from evaporator (1) through liquid        outlet (1 c) of evaporator (1) into mixing unit (5), and from        mixing unit (5) into evaporator (6) through feed inlet (6 a) of        evaporator (6),    -   characterized in that said said-up is the set-up according to        any one of the preceding claims, or    -   characterized in that said set-up further comprises vessel (4′)        and vessel (4″), wherein vessel (4′) is arranged such that a        liquid composition can be fed from vessel (4′) into mixing unit        (2), and/or wherein vessel (4″) is arranged such that a liquid        composition can be fed from vessel (4″) into mixing unit (5).-   6. Use according to embodiment 5, said set-up further comprising    mixing unit (7), wherein said mixing unit (7) is arranged such that    a liquid composition can be fed from evaporator (6) through liquid    outlet (6 c) into mixing unit (7).-   7. Use according to embodiment 6, said set-up further comprising    evaporator (8), said evaporator (8) having a feed inlet (8 a), a    vapor outlet (8 b) and a liquid outlet (8 c),    -   wherein evaporator (8) is arranged such that a liquid        composition can be fed from mixing unit (7) into evaporator (8)        through feed inlet (8 a).-   8. Use according to any one of the preceding embodiments, wherein    mixing unit (2), mixing unit (5) and/or mixing unit (7) is a    homogenizer device and wherein said homogenizer device is preferably    a homogenizer with a pressure drop of at least 50 bar, a colloid    mill, a nozzle, a rotor-stator or a combination thereof.-   9. Use according to any one of the preceding embodiments, wherein    evaporator (1), evaporator (6) and/or evaporator (8) is suitable to    remove an organic solvent and/or is a vertical evaporator, a film    evaporator or a flash vessel.-   10. Use according to any one of the preceding embodiments, said    set-up further comprising an apparatus for spray-drying such as a    spray-drying tower.-   11. Use of the set-up according to any one of the preceding    embodiments wherein said fat-soluble compound is preferably an    edible colorant such as beta-carotene or lycopene.-   12. Use according to embodiment 11, wherein an emulsifier is used to    encapsulate said fat-soluble compound, and wherein the emulsifier is    preferably a polymer, more preferably a colloid, and most preferably    a hydrocolloid.

EXAMPLES

The present invention is further illustrated by the following examples.The examples are not meant to limit the invention in any way.

Example 1a

In Example 1a, the process concept shown in FIG. 4 is being used.

In a steered 2-liter vessel, 389 g modified food starch (commerciallyavailable HiCap®) is dissolved in 908 g water at 76° C. Thus, the2-liter vessel contains approximately 1 liter of a liquid.

In a separate, steered 2-liter vessel, 83.6 g beta-carotene, 10.3 gdl-alpha tocopherol and 34.1 g corn oil are dispersed in 422.0 g ethylacetate. The thus obtained dispersion is heated above the dissolutiontemperature to 121° C., resulting in a 15 weight-% beta-carotenesolution. Thus, the 2-liter vessel contains approximately 0.5 liter of aliquid.

Instead of mixing the two compositions in one step, the process conceptshown in FIG. 4 is followed. As a result, the emulsification mass ratioremained significantly below 30% at any time.

As mixing unit, an emulsification device is used. It is a rotor-statorfollowed by sapphire orifice (diameter 280 μm). The rotor speed of therotor-stator was 5000 rpm, the pressure drop over the orifice of mixingunit was 75 bar, and the temperature was 85° C.

To remove the solvent, the output of mixing unit is fed into anevaporator through its feed inlet. Within the evaporator, the solventand a minor part of the water is removed. In the present example, a finefilm evaporator is used at 72° C. and 657 mbar.

The final dispersion has a beta-carotene content of 4.7 weight-%, basedon the total weight of the dispersion. The dispersion's particles havean average particle size of 299 nm [mean size by cumulant, measured byPhoto Correlation Spectroscopy (Beckman Coulter N4 Plus SubmicronParticle Sizer)]. When spray-drying this composition, a powdercomprising approx. 15.4 weight-% beta-carotene, based on the totalweight of the powder, is expected to be obtained.

Example 1b (Comparative Example)

Example 1a is repeated. However, the process concept shown in FIG. 1 isapplied.

In a steered 2-liter vessel, 389 g modified food starch is dissolved in908 g water at 76° C. Thus, said 2-liter vessel contains approximately 1liter of a liquid.

In a separate, steered 2-liter vessel, 83.6 g beta-carotene, 10.3 gdl-alpha tocopherol and 34.1 g corn oil are dispersed in 422 g ethylacetate. The thus obtained dispersion is heated above dissolutiontemperature to 120° C., resulting in a 15 weight-% beta-carotenesolution. Thus, the 2-liter vessel contains approximately 0.5 liter of aliquid.

As soon as the whole amount of the beta-carotene is dissolved, thelipophilic compounds are being added upstream of a mixing unit to thehydrophilic matrix phase.

As mixing unit, an emulsification device is used. The mixing unit is arotor-stator followed by sapphire orifice (diameter 280 μm). The rotorspeed of the rotor-stator was 5000 rpm, the pressure drop over theorifice of mixing unit was 76 bar, and the temperature was 86° C.

The output of mixing unit is an aqueous liquid which contains one typeof particles only: The core of said particles comprises beta-carotene,corn oil and solvent (=ethyl acetate), i.e. the output of mixing unitcontains ethyl acetate.

To remove the solvent, the output of mixing unit is then fed into anevaporator. Within the evaporator, the solvent and a minor part of thewater is removed. In the present example, a fine film evaporator is usedat 73° C. and 600 mbar.

The final dispersion ready to be spray-dried exits the liquid outlet ofthe evaporator and has a beta-carotene content of 3.3 weight-%, based onthe total weight of the dispersion. The dispersion's particles have anaverage particle size of 593 nm [mean size by cumulant, measured byPhoto Correlation Spectroscopy (Beckman Coulter N4 Plus SubmicronParticle Sizer)].

Example 2 (Measurement of Filter Residue)

To check the quality of the final dispersion (i.e. of the dispersionready to be spray-dried), the dispersion's amount of filter residue isdetermined by filtration. Low filter residue means good quality, i.e.suitable to be spray-dried.

The following method is used:

A sample of the dispersion to be tested is taken and the mass fractionof carotenoid (w_(s)) in the sample is determined by UV/Vis.

Approximately 500-1500 mg of the sample (sample (m_(s)) is taken andmass of carotenoid in sample (m_(s)×w_(s)) is calculated. The sample isthen suspended in 250 ml H₂O (60° C.), filtrated over a 2 g Hyflo SuperCel® (CAS 68855-54-9, crystalline silicic acid, bulk density: 300 kg/m³,available at Merck KGaA) on a filter paper (Whatman 1001-070, Grade 1,median pore size of 7.0 μm) and washed with 500 ml H₂O (60° C.). Theaqueous liquid is waste, i.e. is discharged.

The filter residue is then washed down from the filter withapproximately 100 ml acetone and 40 ml dichloromethane. Dichloromethaneis an excellent solvent for carotenoids and thus, the obtainedResidual-Solution (RS) contains the filter residue. The mass ofcarotenoid in the Residual-Solution (m_(Caro.r)) is then determined.

Then filter residue is calculated as follows:

FR=m _(Caro.r) /m _(Caro.s)×100

FR=Filtration Residue in %

m_(Caro.r)=mass of Carotenoid in Residual-Solution (RS)

m_(Caro.s)=mass of Carotenoid in sample (m_(s)×w_(s))

Any filtration residue below 4 weight-% of the total weight of thedispersion is ideal. A filtration residue of more than 10 weight-% ofthe total weight of the composition indicates the presence of notproperly emulsified carotenoid.

The filtration residue of the dispersions of example 1a and ofcomparative example 1b have been measured. The results are shown inbelow Table 1.

TABLE 1 comparative example example 1a 1b filtration residue 2.4weight-%, based on 53.2 weight-%, based the total weight of the on thetotal weight of dispersion the dispersion

Thus, using the process according to the invention has reducedfiltration residue by approximately factor 35. This tremendousimprovement is due to the compositions' emulsification mass ratio beforeevaporation. It example 1b, it is a lot higher (˜30%) and probably abovethe system's critical emulsification mass ratio.

Examples 3a and 3b (Replacement of Modified Starch)

Examples 1a and 1b were repeated. This time, however, a different kindof modified starch (Capsul® instead of HiCap®) was used. Furthermore, nooil was used. A comparison of the compositions used in examples 1a/1band in examples 3a/3b is shown in below Table 2.

TABLE 2 examples 1a/1b examples 3a/3b composition in beta-carotenebeta-carotene vessel (3) at the dl-alpha tocopherol dl-alpha tocopherolbeginning of the corn oil — process ethyl acetate ethyl acetatecomposition in HiCap ® Capsul ® vessel (4) at the Water Glucidex ®(Glucose Sirup) beginning of the Sodium ascorbate process Water

In example 3a, the process of the invention was used. In example 3b(=comparative example), the process of the prior art was used.

The filtration residue of the dispersions of example 3a and ofcomparative example 3b have been measured as explained in example 2. Theresults are indicated in below Table 3.

TABLE 3 example 3a comparative example 3b filtration 3.9 weight-%, basedon the 54.9 weight-%, based on the residue total weight of thedispersion total weight of the dispersion

The final dispersion obtained in example 3a has a beta-carotene contentof 4.1 weight-%, based on the total weight of the dispersion. Thedispersion's particles have an average particle size of 171 nm [meansize by cumulant, measured by Photo Correlation Spectroscopy (BeckmanCoulter N4 Plus Submicron Particle Sizer)]. When spray-drying thiscomposition, a powder comprising approx. 10.7 weight-% beta-carotene,based on the total weight of the powder, is expected to be obtained.

Examples 3a and 3b confirm that filtration residue can be reduced whenusing the process of the invention.

Examples 4a and 4b (Lycopene)

Examples 1a and 1b were repeated. This time, however, a different kindof fat-soluble compound (lycopene instead of beta-carotene) was used.Furthermore, no oil was used. A comparison of the compositions used inexamples 1a/1b and in examples 4a/4b is shown in below Table 4.

TABLE 4 examples 1a/1b examples 4a/4b composition in beta-carotenelycopene vessel (3) at the dl-alpha tocopherol dl-alpha tocopherolbeginning of the corn oil ethyl acetate process ethyl acetatecomposition in HiCap ® Capsul ® vessel (4) at the Water Glucidex ®(Glucose Sirup) beginning of the Sodium ascorbate process Water

In example 4a, the process of the invention was used. In example 4b(=comparative example), the process of the prior art was used.

The filtration residue of the dispersions of example 4a and ofcomparative example 4b has been measured as explained in example 2. Theresults are shown in below Table 5.

TABLE 5 example 4a comparative example 4b filtration 3.6 weight-%, basedon the 43.8 weight-%, based on the residue total weight of thedispersion total weight of the dispersion

Thus, examples 4a and 4b confirm that filtration residue can be reducedwhen using the process of the invention.

Examples 5a and 5b (Isopropyl Acetate)

Examples 1a and 1b were repeated. This time, however, a different kindof solvent (isopropyl acetate instead of ethyl acetate) was used. Acomparison of the compositions used in examples 1a/1b and in examples5a/5b is shown in below Table 6.

TABLE 6 examples 1a/1b examples 5a/5b composition in beta-carotenebeta-carotene vessel (3) at the dl-alpha tocopherol dl-alpha tocopherolbeginning of the corn oil corn oil process ethyl acetate isopropylacetate composition in HiCap ® HiCap ® vessel (4) at the Water Waterbeginning of the process

In example 5a, the process of the invention was used. In example 5b(=comparative example), the process of the prior art was used.

The filtration residue of the dispersions of example 5a and ofcomparative example 5b have been measured as explained in example 2. Theresults are indicated in below Table 7.

TABLE 7 example 5a comparative example 5b filtration 2.1 weight-%, basedon the 35.9 weight-%, based on the residue total weight of thedispersion total weight of the dispersion

Thus, examples 5a and 5b confirm that filtration residue can be reducedwhen using the process of the invention.

Furthermore, the beta-carotene content of the dispersion of example 5ahas been determined by UV/VIS. A content of 7.3 weight-%, based on thetotal weight of the dispersion, was measured. If such a dispersion isspray-dried, the obtained powder is expected to have a beta-carotenecontent of approx. 24.0 weight-%, based on the total weight of thepowder.

Examples 6a and 6b (Gelatin)

Examples 1a and 1b were repeated. This time, however, a different kindof emulsifier/colloid (gelatin instead of modified starch) was used. Acomparison of the compositions used in examples 1a/1b and in examples6a/6b is shown in below Table 8.

TABLE 8 examples 1a/1b examples 6a/6b composition in beta-carotenebeta-carotene vessel (3) at the dl-alpha tocopherol dl-alpha tocopherolbeginning of the corn oil corn oil process ethyl acetate ethyl acetatecomposition in HiCap ® Fish gelatin (dried) vessel (4) at the Watersucrose beginning of the ascorbyl palmitate process water

In example 6a, the process of the invention was used. In example 6b(=comparative example), the process of the prior art was used.

The filtration residue of the dispersions of example 6a and ofcomparative example 6b have been measured as explained in example 2. Theresults are indicated in below Table 9.

TABLE 9 example 6a comparative example 6b filtration 1.6 weight-%, basedon the 79.9 weight-%, based on the residue total weight of thedispersion total weight of the dispersion

Thus, examples 6a and 6b confirm that filtration residue can be reducedwhen using the process of the invention.

Furthermore, the beta-carotene content of the dispersion of example 6ahas been determined by UV/VIS. A content of 14.9 weight-%, based on thetotal weight of the dispersion, was measured. If such a dispersion isspray-dried, the obtained powder is expected to have a beta-carotenecontent of approx. 37.1 weight-%, based on the total weight of thepowder.

Example 6 clearly shows that the technical effects of the invention areparticularly evident if highly concentrated powders are to bemanufactured.

1. A set-up comprising evaporator, mixing unit, vessel, vessel andmixing unit, wherein evaporator has a feed inlet, a vapor outlet and aliquid outlet, and wherein evaporator, mixing unit, vessel and mixingunit are arranged such that a liquid composition can be fed from vesselinto mixing unit and from mixing unit into evaporator through feed inletof evaporator and from evaporator through liquid outlet of evaporatorinto mixing unit, characterized in that vessel is arranged such that aliquid composition can be fed from vessel into mixing unit and intomixing unit.
 2. The set-up according to claim 1, wherein the set-upcomprises means to control the flow from vessel into mixing unit and/orinto mixing unit, and wherein the set-up preferably comprises a pump tocontrol the flow from vessel into mixing unit and/or wherein the set-uppreferably comprises a pump to control the flow from vessel into mixingunit, and/or wherein the set-up comprises means to control the flow fromvessel into mixing unit, and wherein vessel is preferably provided witha pump to control the flow from vessel into mixing unit.
 3. The set-upaccording to claim 1, wherein vessel is connected to mixing unit byconnection, wherein said connection is preferably a tube, a pipe, achannel, a funnel, a course, a conduit or a duct, and/or wherein saidconnection has preferably a length of at least 2 meters, more preferablyof at least 10 meters and most preferably of at least 100 meters.
 4. Theset-up according to claim 1, wherein each of said vessels and is capableof holding a volume of at least 100 liters, preferably of at least 500liters and most preferably of at least 3000 liters.
 5. A set-upcomprising evaporator, mixing unit, vessel, mixing unit and evaporator,wherein evaporator has a feed inlet, a vapor outlet and a liquid outlet,and wherein evaporator has a feed inlet, a vapor outlet and a liquidoutlet, and wherein evaporator, mixing unit, vessel, mixing unit andevaporator are arranged such that a liquid composition can be fed fromvessel into mixing unit, and from mixing unit into evaporator throughfeed inlet of evaporator and from evaporator through liquid outlet ofevaporator into mixing unit, and from mixing unit into evaporatorthrough feed inlet of evaporator, wherein said said-up is the set-upaccording to claim 1, or characterized in that said set-up furthercomprises vessel and vessel, wherein vessel is arranged such that aliquid composition can be fed from vessel into mixing unit, and/orwherein vessel is arranged such that a liquid composition can be fedfrom vessel into mixing unit.
 6. The set-up according to claim 5,further comprising mixing unit, wherein said mixing unit is arrangedsuch that a liquid composition can be fed from evaporator through liquidoutlet into mixing unit.
 7. The set-up according to claim 6, furthercomprising evaporator, said evaporator having a feed inlet, a vaporoutlet and a liquid outlet, wherein evaporator is arranged such that aliquid composition can be fed from mixing unit into evaporator throughfeed inlet.
 8. The set-up according to claim 1, wherein mixing unit,mixing unit and/or mixing unit is a homogenizer device and wherein saidhomogenizer device is preferably a homogenizer with a pressure drop ofat least 50 bar, a colloid mill, a nozzle, a rotor-stator or acombination thereof.
 9. The set-up according to claim 1, whereinevaporator, evaporator and/or evaporator is suitable to remove anorganic solvent and/or is a vertical evaporator, a film evaporator or aflash vessel.
 10. The set-up according to claim 1, further comprising anapparatus for spray-drying such as a spray-drying tower.
 11. A processfor the preparation of a powder comprising at least one fat-solublecompound, wherein the process comprises the steps of a) providing asolution comprising at least one fat-soluble compound, at least onesolvent and optionally at least one oil, b) providing a compositioncomprising water and at least one emulsifier, c) adding a fraction ofthe solution of step a) to a fraction of the solution of step b) undervigorous stirring, d) removing said at least one solvent at leastpartially by heating the composition of step c) at a pressure of lessthan 1500 mbar e) adding an additional fraction of composition of stepa) to the composition of step d) under vigorous stirring, and f)removing said at least one solvent at least partially by heating thecomposition of step e) at a pressure of less than 1500 mbar.
 12. Theprocess of claim 11, further comprising the steps of g) adding anadditional fraction of composition of step a) to the composition of stepf) under vigorous stirring, and h) removing said at least one solvent atleast partially by heating the composition of step g) at a pressure ofless than 1500 mbar.
 13. The process of claim 1, and wherein thesolution provided in said step a) is put into vessel or into vessel andvessel of the set-up, and/or wherein said composition provided in saidstep b) is put into vessel of the set-up.
 14. The process according toclaim 12, wherein said solvent is at least one water immiscible organicsolvent being preferably dichloromethane, ethyl acetate or isopropylacetate, and/or wherein said fat-soluble compound is an edible colorantbeing preferably beta-carotene or lycopene.
 15. The composition obtainedin step f) of the process according to claim 11 or the compositionobtained in step g) of the process.